Diagnostic Value of Flexible Thoracoscopy in Undiagnosed Cases of Exudative Pleural Effusion

Abstract

Vengada Krishnaraj S.P. 1 , Gayathri S. Mohan2 , V. Vinod Kumar3 , R. Sridhar4

BACKGROUND The diagnostic yield of thoracoscopy is 95 %, of pleural fluid cytology it is 62 % and of closed pleural biopsy is 44 %, in malignant effusion. We wanted to study the diagnostic utility of flexible thoracoscopy in undiagnosed exudative pleural effusion and compare the thoracoscopy findings with the histopathology results. METHODS The study was conducted in the Department of Respiratory Medicine, Government Stanley Medical College, Chennai, from January 2019 to January 2020. 40 patients were enrolled in this longitudinal observational study with moderate to massive effusion and were evaluated with pleural fluid aspiration and sent for cytology, protein sugar analysis, total count, and ADA. Those cases which are exudative pleural effusions, with ADA value of less than 40 IU / L were subjected to thoracoscopy after being evaluated for fitness for thoracoscopy with complete blood count, bleeding time, clotting time, sputum for AFB, ECG, pulse oximetry, cardiac evaluation and CT chest. RESULTS Thoracoscopy was done in 40 enrolled patients. In this study, biopsy was taken from the parietal pleura in all the cases. Of these 40 cases, 30 were male and 10 were female, that is 75 % males and 25 % females. The mean age of the study population was 43 ± 14.9. Patient with the lowest age in this study group was 18 years and highest was 71 years. 16 cases (40 %) presented with left sided pleural effusion. 24 cases (60 %) presented with right sided pleural effusion. 30 cases presented with massive effusion, and 10 cases with moderate effusion. Of the 40 cases, 27 cases presented with straw coloured pleural effusion. 13 cases were haemorrhagic effusion. Histopathologic examination showed 11 cases as malignant and 29 cases as non-malignant out of which 18 cases were of tuberculosis aetiology. Thoracoscopy revealed adhesions in 13 cases and mass lesion in 4 cases. Of the 4 mass lesions 3 came as malignant, normal pleura in 11 cases, 10 were non-malignant and 1 was malignant. Nodules were seen in 12 cases of which 7 came as malignant. Straw coloured effusion was seen in 27 cases, of which 2 were malignant. CONCLUSIONS The most important indication for thoracoscopy is exudative undiagnosed pleural effusion. The overall diagnostic yield in pleural fluid cytology is 62 % and blind pleural biopsy is 44 %. The diagnostic yield of thoracoscopy varies from 60 % to 97 % in various studies, whereas, in our study, it is 72.5 %. Visualization of the visceral and parietal pleura is another advantage, so that we can take biopsy from the abnormal areas.

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